1,150 research outputs found

    Five new species and three new subspecies of Erebidae and Noctuidae (Insecta, Lepidoptera) from Northwestern North America, with notes on Chytolita Grote (Erebidae) and Hydraecia Guenée (Noctuidae)

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    This is the publisher’s final pdf. The published article is copyrighted by Pensoft Publishers and can be found at: http://www.pensoft.net/journals/zookeys/.Several taxonomic issues in the moth families Erebidae and Noctuidae are addressed for Northwestern North America. Drasteria parallela Crabo & Mustelin and Cycnia oregonensis tristis Crabo in the Erebidae and Eudryas brevipennis bonneville Shepard & Crabo, Resapamea diluvius Crabo, Resapamea angelika Crabo, Resapamea mammuthus Crabo, Fishia nigrescens Hammond & Crabo, and Xestia perquiritata orca Crabo & Hammond in the Noctuidae are described as new. The following new synonyms are proposed: Chytolita petrealis Grote with Herminea morbidalis Guenee; Gortyna columbia Barnes & Benjamin and Gortyna ximena Barnes & Benjamin with Gortyna obliqua Harvey; and Hydroecia pallescens Smith with Hydroecia medialis Smith. The type locality of Gortyna intermedia Barnes & Benjamin is restricted to Lundbreck, Municipality of Crowsnest Pass, Alberta, Canada

    Coronal lines and the importance of deep core-valence correlation in Ag-like ions

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    We report on large-scale and critically evaluated {\em ab initio} MCDHF calculations of the wavelength of the "coronal", M1 transition $4f\ ^2\mathrm{F}_{5/2}^o-^2\mathrm{F}_{7/2}^oinAg−likeions.Thetransitionbetweenthesetwofinestructurelevels,whichmakesupthegroundtermfor in Ag-like ions. The transition between these two fine structure levels, which makes up the ground term for Z \ge 62intheisoelectronicsequence,hasrecentlybeenobservedinYb in the isoelectronic sequence, has recently been observed in Yb^{23+}andW and W^{27+},wherethelattercouldbeofgreatimportanceforfusionplasmadiagnostics.Wepresentrecommendedvaluesforallmembersofthesequencebetween, where the latter could be of great importance for fusion plasma diagnostics. We present recommended values for all members of the sequence between Z = 50and and 94,whicharesupportedbyexcellentagreementwithvaluesfromrecentexperiments.Theimportanceofincludingcore−valencecorrelationwiththe, which are supported by excellent agreement with values from recent experiments. The importance of including core-valence correlation with the n=3$ shell in the theoretical model is emphasized. The results show close to spectroscopic accuracy for these forbidden lines.Comment: 10 pages, 5 figures, 3 table

    Epitaxial growth and characterization of (001) [NiFe/M]20 (M = Cu, CuPt and Pt) superlattices

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    We present optimization of [(15 \uc5) Ni80Fe20/(5 \uc5) M]20 single crystal multilayers on (001) MgO substrates, with M being Cu, Cu50Pt50 and Pt. These superlattices were characterized by high resolution X-ray reflectivity (XRR) and diffraction (XRD) as well as polar mapping of important crystal planes. It is shown that cube on cube epitaxial relationship can be obtained when depositing at substrate temperature of 100 \ub0C regardless of the lattice mismatch (5% and 14% for Cu and Pt, respectively). At lower substrate temperatures poly-crystalline multilayers were obtained while at higher substrate temperatures {111} planes appear at ∌10\ub0 off normal to the film plane. It is also shown that as the epitaxial strain increases, the easy magnetization axis rotates towards the direction that previously was assumed to be harder, i.e. from [110] to [100], and eventually further increase in the strain makes the magnetic hysteresis loops isotropic in the film plane. Higher epitaxial strain is also accompanied with increased coercivity values. Thus, the effect of epitaxial strain on the magnetocrystalline anisotropy is much larger than what was observed previously in similar, but polycrystalline samples with uniaxial anisotropy (Kateb et al. 2021)

    Foundations of physical vapor deposition with plasma assistance

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    Physical vapor deposition (PVD) refers to the removal of atoms from a solid or a liquid by physical means, followed by deposition of those atoms on a nearby surface to form a thin film or coating. Various approaches and techniques are applied to release the atoms including thermal evaporation, electron beam evaporation, ion-driven sputtering, laser ablation, and cathodic arc-based emission. Some of the approaches are based on a plasma discharge, while in other cases the atoms composing the vapor are ionized either due to the release of the film-forming species or they are ionized intentionally afterward. Here, a brief overview of the various PVD techniques is given, while the emphasis is on sputtering, which is dominated by magnetron sputtering, the most widely used technique for deposition of both metallic and compound thin films. The advantages and drawbacks of the various techniques are discussed and compared

    A first spectroscopic measurement of the magnetic field strength for an active region of the solar corona

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    For all involved in astronomy, the importance of monitoring and determining astrophysical magnetic field strengths is clear. It is also a well-known fact that the corona magnetic fields play an important part in the origin of solar flares and the variations of space weather. However, after many years of solar corona studies, there is still no direct and continuous way to measure and monitor the solar magnetic field strength. We will here present a scheme which allows such a measurement, based on a careful study of an exotic class of atomic transitions known as magnetic induced transitions in Fe9+^{9+}. In this contribution we present a first application of this methodology and determine a value of the coronal field strength using the spectroscopic data from HINODE

    Growth of HfN thin films by reactive high power impulse magnetron sputtering

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    Publisher's version (Ăștgefin grein)Thin hafnium nitride films were grown on SiO2 by reactive high power impulse magnetron sputtering (HiPIMS) and reactive direct current magnetron sputtering (dcMS). The conditions during growth were kept similar and the film properties were compared as growth temperature, nitrogen flow rate, and in the case of HiPIMS, duty cycle were independently varied. The films were characterized with grazing incidence X-ray diffraction (GIXRD), X-ray reflection (XRR) and X-ray stress analysis (XSA). HiPIMS growth had a lower growth rate for all grown films, but the films surfaces were smoother. The film density of HiPIMS deposited films grown at low duty cycle was comparable to dcMS grown films. Increasing the duty cycle increased the density of the HiPIMS grown films almost to the bulk density of HfN as well as increasing the growth rate, while the surface roughness did not change significantly. The HiPIMS grown films had large compressive stress while the dcMS grown films had some tensile stress. The dcMS grown films exhibit larger grains than HiPIMS grown films. The grain size of HiPIMS grown films decreases with increasing nitrogen flow rate, while the dcMS grain size increased with increasing nitrogen flow rate. This work shows that duty cycle during HiPIMS growth of HfN films has a significant effect on the film density and growth rate while other film properties seem mostly unaffected.This work was partially supported by the Icelandic Research Fund Grant No. 163086 and the Swedish Government Agency for Innovation Systems (VINNOVA) contract no. 2014-04876.Peer Reviewe
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